Field of the Invention
The invention relates to a method for operating a postpress processing installation for producing and processing of printed products, in particular for forming stacks or packages from collections of printed products consisting of completed final printed products such as periodicals and newspapers, which are preferably compiled from a jacket product and a plurality of part products and/or inserts. The present invention relates in addition to a postpress processing installation for the implementation of the method.
Ever greater demands are being placed on postpress processing with increasing regionalization and/or personalization of the editorial content of the products, but in particular of the advertising inserts. On the one hand, there is a need to increase the processing capacity in order to increase profitability, and on the other hand the products must also be capable of being made ready for despatch faultlessly with the smallest possible manual effort, even for small distribution routes or regions.
In the highly competitive advertising market, increasingly high expectations are imposed on the providers of print advertising and thus on postpress processing, and fewer and fewer defects are tolerated. Since advertising clients are only prepared to accept very low defect rates in the low promille range, any defects in the compilation of the products must be avoided or must undergo time-consuming and expensive rectification by hand.
Discussion of Related Art
Different methods are familiar from the prior art for ensuring that the products are compiled in the correct succession or sequence in order to keep the manual repair costs as low as possible.
A method and a device for creating a product stream from a plurality of product units in a predetermined sequence are thus proposed in WO 2013/159238, for example, by means of which defective product units in a sequence can be rectified without any interruption of production and while respecting the predetermined sequence. In this method for creating a synchronized product stream of product units, products are fed to the grouping section of a first conveyor device in a predetermined sequence in a first step, and a synchronized product stream of product units is then produced from the fed products along the grouping section in a predetermined sequence, and the product units are transferred in the predetermined sequence to a transfer conveyor device and are transported away in a synchronized product stream.
In the event of defects arising in the course of producing the products, these can be rectified subsequently by the ejection of individual products or the entire defective product unit at an ejection station, and by producing the product unit in an enhanced or completely new form. It is proposed in particular, however, that, in the event of the failure of only individual products in the product unit, the imperfect product units are fed back to the grouping section and are completed.
The faulty or defective product unit is also subsequently prepared correctly in the grouping section and is then transferred to the transfer conveyor device. In order to introduce this product unit subsequently for the reinstatement of the predetermined product sequence at the correct position within this sequence, a bridging device is proposed in WO 2013/159238, which makes it possible, by bridging a section of the conveyor path of the transfer conveyor device, to feed it subsequently to the product gap. In this way, the predetermined sequence of product units is made available in the transfer conveyor device in a fully sorted sequence for further process operations. The product units are preferably individualized and, for example, are assigned to a specific recipient or a specific recipient's address.
EP 0511159 describes a method and a device, which serve for the compilation of predetermined sequences of complex product units by the insertion of part products into a main product, the intention being to prevent the occurrence of defective groups. In the process, different products supplied as continuous streams along at least one grouping section, provided by a belt conveyor, are collated into groups. Each group is intended to include a predetermined sequence of products. In order to avoid defects in the deposited product stream because of defects in the feeding, it is proposed to continue to buffer the products in the feed streams ahead of their discharge into the grouping section, e.g. by means of corresponding intermediate conveyors. Discharging should only take place if an adequate number of products to create a complete group is present in all the buffers. If necessary, the creation of a group is delayed until this is the case. This takes place substantially in three process steps: feed control of the individual feeds, feed buffering of the individual feeds and controlled discharge of the individual products into a synchronized grouping. The feed control is used to detect defects, or gaps, in the product feeds. The controlled discharge, which is subject to the same rate as the grouping, is used to discharge the supplied products according to the predetermined composition of the individual groups and according to the detected defects in the grouping. A continuous feed is made possible by the feed buffering, in spite of the non-continuous discharge.
The aforementioned devices for the rectification of defects in the production of final printed products and for ensuring the correct product sequence make the installations for postpress processing more expensive and make them considerably more complex in respect of the mechanics, but also the control.
Accordingly, it is often dispensed with, and personalized final printed products that have been rectified or produced in additional quantities subsequently require to be introduced manually into the correct position within their route sequence. In postpress processing installations, which possess an automatic repair function, for example incompletely combined collections can be completed in a further pass. However, this means that at least the stacking device must wait for the rectified end products for the duration of the repair cycle, or, in the case of complete post-production, for the end products that have been produced in additional quantities. This waiting time significantly reduces the output of the installation.